Cellulose-ether composition



To all whom it may concern:

Patented Sept. 1925.

UNITED STATES PATENT OFFICE.

JOZEIN M. DONOHUE, or ROCHESTER, NEW Yoargiissrenort To EASTMAN KODAK COMPANY, or, ROCHESTER, New 55031;, A CORPORATION or NEW YORK.

CELLULOSE-ETHER colvrrosrrroizr.

No Drawing. 1

Be it known that I, JoriuM; DoNoHUu, a citizen of the United States of America, residing at Rochester, in the county; of Monroe and State of New York. have invented certain new and useful Improvements in Cellulose-Ether Compositions, of which the following is a full 'clear, and exact spec1fi cation.

This invention relates to solvents for making strong solutions of cellulose ether and also relates to the cellulose ether compositions produced by the aid of such solvents. One object of my invention is to'provide a solvent which will dissolve such large proportions of cellulose ethers that thick or viscous flowable solutions may be obtained for use in plastic, and film making. arts. Another object of my invention is to provide a cellulose ether solution which may be manufactured into strong, flexible, transparent films on the machines and by the methods now in use. Other objects will hereinafter appear.

In U. S. Patent No. 1,188,376, Lilienfeld, June 20, 1916, there are disclosed a series of alkyl ethers of cellulose. Certain of these are practically insoluble in water. and my invention relates, but is not limited, to the others having that property. IVhile cellulose ethers form thin solutions in the lower monohydroxy aliphatic-alcohols or in. hexyl acetate, it has been found that such single solvents by themselves do not dissolve a sufficient proportion of the ethers to make a desirably thick flowable composition or dope, such as may be used-in the. manufacture of photographietilm base by customary methods or in the other plastic arts. I have discovered that an adequately I strong and useful solvent maybe prepared by mixing hexyl acetate with one or more of 'the lower monohydroxy aliphatic alcohols. In other words, I have discovered that mixtures of these ingredients have a greater solvent action on cellulose others than similar weights of such ingredients when -employed by themselves. By lower monohydroxy aliphatic alcohols, I mean those having less than six carbon atoms. i

\Vhile the ingredients maybe mixed in widely varying proportions it is'noted, by way of example, that a particularly useful composition can be. prepared by mixing equal parts by weight of hexyl acetate with Application filed February 23, 1923. Serial No. 620,612.

acetate and a lower m the aliphatic] alcohol, say methyl alcohol.

In the preferred form of my invention, I. dissolve 1 part f by Weight ofthe'cellulose ether, say watef insolubl'e ethyl cellulose, in from .5 to 7 parts bywveight of the solvent mixture. Theingredient by themselves are not sufliciently powerfu 0 make properly flowable solutions of this strength. Of

course, the proportion ofhiixed solvent or the proportion of the volatile ingredients maybe increased to adapt the composition to the lacquering art, as will be understood by skilled persons. I

Other substances which impart additional suppleness, or incombustibility, or other qualities, to the film may also be added to the dope, such, for instance, as triphenyl or tricresyl phosphate, monochlornaphthalene, ramphor, etc. The ingredients are of the ordinary (Oll'linelCl'fil type and sufiiciently purified for the process of film manufacture. so as-to give a dope yielding films having the properrelative; freedom from color.

The viscous-flowable\ clo'pe above described can he used in connection with the usual film-forming apparatuswithout the necessity of expensive alterations in the latter.

In the formation ofafijlm by the evaporation of the volatile-.:in;rredieuts from the hereinabo-ve described compositions, a considerable amount of hexyl acetate remains behind, because of it's relatively low volatility It imparts useful plastifying; and other properties to the film, which is normally flexible and transparent.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:,

1. A composition of matter comprising cellulose etherand hexyl acetate, the ingredients being homogeneously mixed in unprecipitated form.

2. A- composition of matter comprising cellulose ether dissolved in a mixture of h'exyl acetate and alower monohydroxy' aliphatic alcohol.

3. A composition of matter comprising cellulose ether dissolved in a mixture of heXyl acetate and methyl alcohol.

.'4- A flowable composition comprising 1 part of cellulose ether dissolved in from 5.

'7 parts by weight of a mixture of hexyl onohydroxy aliphatic alcohol.

5. A composition of matter comiorisine' of methyl alcohol.

cellulose ether dissolved in a mixture of, sub- 'stantially equal parts by weight of hexyl acetate and a lower monohydroxy aliphatic alcohol. v

v -6. A composition of matter comprising 2 parts by weight of Water-insoluble ethyl cellulose, 7 parts of hexyl acetate and 7 parts 7; As an article of manufacture, a film comprising cellulose ether and hexyl acetate.

8. As an article of manufacture, a tough flexible transparent film comprising'waterinsoluble ethylcellulose and ,hexyl acetate.

Signed at'Rochester, New. York this 14th day of February 1923.

JOHN M. DONOHUE. 

